5V/3.3V ClockWorks HIGH-PERFORMANCE SY89421V FINAL PHASE LOCKED LOOP FEATURES DESCRIPTION 3.3V and 5V power supply options The SY89421V is a digital Phase Locked Loop based on Micrel-Synergy s differential PLL technology. It is capable 1.12GHz maximum VCO frequency of operating in the 30MHz to 560MHz reference input 30MHz to 560MHz reference input operating frequency range, and up to 2000MHz with the HFIN input frequency and an external VCO. Use of a phase-frequency detector External 2.0GHz VCO capability results in excellent PLL locking and tracking characteristics. Low jitter differential design Error correction voltages are generated by the detector if either phase or frequency deviations occur. The VCO has Frequency doubler mode a frequency range covering more than a 2:1 ratio from PECL Differential output 480MHz to 1120MHz. External loop filter optimizes performance/cost Feedback for the loop is realized by connecting FOUT, Available in 20-pin SOIC package FOUT to FIN, FIN by means of external circuitry. This allows the flexibility of inserting additional circuitry off-chip in the feedback paths, such as an additional divider and/or buffer. Pulldown resistors are required for the FOUT and APPLICATIONS FOUT pins. High frequency inputs HFIN, HFIN and corresponding outputs HFOUT, HFOUT are featured for Workstations use with external components such as an active loop filter and a high frequency VCO. Advanced communications Select pins S1 and S2 are used to program the N divider High-performance computing for optimum VCO operation, in other words with the VCO in the center of its range. Select pin S3 allows bypassing the N divider enabling the PLL to output the VCO directly. PIN CONFIGURATION Select pin S4 is used to select off-chip or on-chip VCO. Select pin S5 enables the divide-by-two prescaler, which is useful in frequency doubling applications. All Select pins are TTL compatible. S1 1 20 S2 FIN 2 19 RIN FIN 3 18 RIN VEE 4 17 S3 F1 5 16 VCC TOP VIEW SOIC F2 FOUT 6 Z20-1 15 S5 7 14 FOUT HFIN 8 13 VCCO HFIN 9 12 HFOUT S4 10 11 HFOUT Rev.: F Amendment: /0 Issue Date: May 2000 1ClockWorks Micrel SY89421V BLOCK DIAGRAM F1 F2 HFIN LOOP RIN FILTER D HFIN RIN 2 PHASE-FREQUENCY VCO DETECTOR FIN P 01 (1, 2) S4 FIN MUX S5 HFOUT HFOUT S1 N S2 (1,2,4,8,10,12,16,20) S3 FOUT FOUT LOOP FILTER COMPONENT SELECTION R C F1 F2 C = 1.0 F 10% (X7R dielectric) R = 560 10% 2